Technical Field
The present invention relates generally to connectors for connecting electrical cables and flexible conduits to electrical panels, and more particularly to an improved connector that allows easier insertion of a cable into the trailing end of a connector and of the connector into a panel.
Background Art
It is common to use electrical junction boxes or panels in electrical construction wiring. The junction boxes or panels have knock out holes or apertures where electrical cables are connected. For present purposes the label “panel” is used interchangeably to mean a junction box or a panel. Also for present purposes, the label “aperture” is used since it generically applies to holes created in any of various manners. For example, a hole created when a pre-made knock out piece is removed from a wall of a panel is a true knock out hole or an aperture. But similarly, a hole made when a smaller hole is drilled and a knock out die-and-screw set is used to punch out a larger hole is also a knock out hole or aperture. And a hole made when drilled to the desired size is an aperture.
Armored and metallic electrical cables are supplied in different nominal sizes in accordance with typical applications. For example, in the United States the National Electrical Code specifies common sizes. The National Electrical Code, or an equivalent standard, will also specify the materials of electrical cables, and/or will specify the electrical continuity, since this controls grounding between the electrical panel, the connector, and the electrical.
Armored cables (AC) and metal-clad cables (MC) have historically been connected to electrical junction boxes or panels with a tubular connector. Such traditional connectors have a leading end with a threaded nose for insertion into an aperture in the panel, and then tightening of a locknut thereon to secure the connector to the panel. Such connectors further have a trailing end with either a screw passing laterally through the connector wall or a strap and either one or two screws. By inserting a cable and then tightening the screw or screws, the cable is secured and retained in the connector.
Regardless of whether for a single family residence, an apartment building, or a factory, a typical construction project can require hundreds to thousands of connectors and their connection. One consideration for a contractor contemplating such a project is the cost of the connectors, which is usually based on the materials used, the energy, steps count, parts count, etc. needed to manufacture the connectors. Another consideration for the contractor usually also is the cost of the labor to make the connections, both of the connector to the panel and of the cable into the connector.
In particular, using such traditional connectors necessitate the use of appropriate tools to achieve a secure connection, such as using a wrench on the lock nut and a screwdriver on the cable securing screw or screws. It should therefore be appreciated that completing all of these connections, using the mentioned tools on each connection, can be very time consuming.
Several types of snap engagement connectors have recently been introduced as a means to reduce the time and effort required for installation. Although these snap engagement connectors generally may partially or even fully eliminate the need to use tools for installation, they still typically require a lot of effort to snap into the apertures in panels. Alternately, if there is a need for a retrofit or disconnection of the connector, workers may then have to use tools to remove each snap engagement connector involved, which in turn will involve a lot of time and effort.
Accordingly, what is needed is an improved connector for securing an electrical cable to an electrical junction box or panel. Such an improved connector should preferably not require the use of any tools for installing or removing the connector, at either the leading or trailing end. Nonetheless, such an improved connector should preferably allow its leading end to connect quickly and securely to the panel as well as for its trailing end to quickly and securely accept connection of a cable. Such a connector will vastly reduce the time and effort involved for installing or removing electrical cables in structure wiring. The desired connectors must be additionally designed to work with standard electrical junction boxes panels, housings, etc., while allowing quick and easy connection with standard size knock out holes or apertures.